410 likes | 624 Views
Sexually Transmitted Diseases. Presented By :. Pradeep Soni. 514a. Stavropol state medical academy Department of asu. Sexually Transmitted Diseases. transmitted during coitus or genital contact 1 in 4 will contract STD between 15-55 yrs of age
E N D
Sexually Transmitted Diseases Presented By : Pradeep Soni 514a Stavropol state medical academy Department of asu
Sexually Transmitted Diseases • transmitted during coitus or genital contact • 1 in 4 will contract STD between 15-55 yrs of age • require moist environments (“transitional zones”)
STDs • common areas of infection: • vulva, vagina urethra in females • penis, urethra in males • mouth, oral cavity, eyes, anus in both sexes • if untreated, can pass from transitional zone to other tissues • person usually has >1 STD as a time
Causes • BACTERIA : • single-celled, microscopic organisms • cause disease by producing toxins • can be prevented by vaccines; killed by antibiotics • Examples of bacterial STDs: chlamydia, gonorrhea, syphilis
Causes • VIRUSES: • tiny, noncellular particle • has DNA or RNA core and a protein coat • parasitic (reproduces in host cell) • some can be prevented by vaccine • Examples of viral STDs: • Herpes genitalis, HPV, HIV • OTHERS: FUNGI, PROTOZOA, INVERTEBRATES
Chlamydia (most prevalent bacterial STD) • caused by bacterium-like microorganism that lives inside cells • symptoms: • urinary tract infection in both males and females • yellowish vaginal discharge • Infected tissues become red, irritated • some may be asymptomatic (30% of males, 50-70% of females)
Chlamydia Life Cycle Chlamydia Cervicitis
Chlamydia • if left untreated, PID can result in females • untreated males can develop infertility (due to scarring of sex accessory tubes) • can be passed from pregnant woman to child during delivery > lung and eye infections in newborn • detected by tissue culture • treated with antibiotics (note: penicillin is ineffective) • association exists between chlamydia and cervical cancer
Gonorrhea • Bacterial STD • Symptoms similar to those of chlamydia
Syphilis • STD caused by bacterium • 1st epidemic: 15th century, W. Europe • bacterium thrives in moist regions • 9/10 cases due to transmission during coitus
Stages of Syphilis:Primary stage • involves single sore (chancre) where bacteria 1st entered the body • appears 10-90 days after entry • heals in 1-5 weeks • afterwards, travels in blood, lymph to other parts of body
Sores Primary Syphilis Chancre
Secondary stage of syphilis • occurs 2 weeks - 6 months after primary stage • characterized by rash on upper body, arms, hands, spreads to other skin • larger bumps develop, burst (release lots of bacteria!) • doesn’t itch; painless • can also cause hair loss, sore throat, headache, loss of appetite, nausea, muscle / joint pain, low fever • sometimes symptoms are overlooked • goes away in 2-6 weeks • enters latent stage
Latent stage of syphilis • can last for years • has few or no symptoms • after 1 yr, bacteria can no longer be transmitted (except to fetus) • 1/2 never leave latent stage • 1/2 enter tertiary stage if not already treated with antibiotics
Tertiary stage of syphilis • bacteria has invaded tissues throughout the body • causes large, tumor-like sores on skin, muscle, internal organs • greatly damages heart, valves • ultimately affects central nervous system > paralysis, blindness, psychotic behavior • 4000 die per year in U.S. due to advanced syphilis
Congenital Syphilis • can be passed from mother to fetus at any stage of syphilis • placenta protects baby up to 6 mo. • then, bacteria enters fetal bloodstream: • 30% miscarry • 70% born with congenital syphilis and go through normal progression of disease • can severely damage developing tissues of newborn; many die
Diagnosis / treatment of syphilis • Cultures; blood test for antibodies • several antibiotics are effective • curable, like gonorrhea • may cause permanent damage if tertiary stage is reached
Herpes genitalis • most common viral STD (1 million in U.S. contract / year) • incurable • caused by herpes simplex type 2 virus • other herpes viruses exist (cause fever blisters, cold sores, chicken pox, infectious mononucleosis) • type 2 invades areas below the waist; type 1 invades above the waist • 20% of infections in genital region are due to type 1
Herpes • likewise, type 2 is sometimes found in mouth sores • condoms not 100% effective in preventing transmission • type 2 can be transmitted by nonsexual contact
Herpes: Symptoms • Burning sensation followed by appearance of blisters • Blisters rupture in 1-2 days; become painful ulcers • Possible flu-like symptoms • in males > sores occur on penis • in females > on labia, clitoris, cervix, vagina, urethra, perineum
Herpes Symptoms • in both sexes: painful urination and coitus; sometimes fever and enlargement of lymph nodes • sores heal between 1-6 weeks • if virus comes into contact with eye, can cause blindness
Herpes: Transmission • even with no sores, virus is harbored within body in nerve cells near spinal cord • a person is most infectious when sores are present; transmission at other times? • sores can reappear throughout a persons lifetime
Herpes: Transmission • triggers for recurrence: • sunlight • stress • menstruation • sex • sometimes, antibodies are developed that alleviate or stop recurrences
Herpes: Treatment • no cure for herpes • drugs can disrupt viral reproduction • some forms resistant • proper hygiene helps reduce spread • vaccine is currently being developed that decreases frequency of sore recurrence
Herpes • vaginal deliveries can result in infection of newborn: • 25% can develop blindness, brain damage • 25% develop skin lesions • rarely, virus can cross placenta
Human papilloma virus • Over 70 strains • Some cause “venereal warts” -moist, soft, cauliflower-like bumps (within 3 weeks - 8 months) • appear on cervix, labia, vulva, perineum in females • on penis in males, urethra, scrotum • treated topically with dry ice, liquid nitrogen > warts dry up and fall off in a few days • warts may recur
Human papilloma virus • major cause of cervical cancer (95% of cases associated with HPV) • also associated with cancer of the penis, vagina, anus
AIDS • AIDS = acquired immune deficiency syndrome: • condition is caught, not inherited • virus attacks immune system • certain infections, cancers occur in infected persons • caused by human immunodeficiency viruses (HIV) • live and reproduce in helper T cells • host cells die as viruses depart to infect other cells • consequence: decrease in helper T cells, which are necessary for stimulating antibody production by B cells and activity of killer T cells
AIDS • between 4.2 and 15 years, HIV infection leads to fullblown AIDs • stages: • “window period” (incubation period): • can be as long as six months • virus replicates slowly; no antibodies detected • “acute phase of HIV disease” (after seroconversion): • lasts 2-4 weeks • accompanied by flu-like illness (fever, swollen glands, muscle aches, weight loss)
AIDS • “asymptomatic phase”: • little or no symptoms • virus continues to replicate, destroy T cells • “symptomatic phase”: • opportunistic infections begin • examples: bacterial skin infections, diarrhea, fever, tuberculosis
AIDS • T cell count less than 200 cells per microliter of blood (normal is 900-1200 cells) • accompanied by one or more opportunistic infections: • pneumonia • neurological problems (meningitis, seizures) • cancers of skin, cervix, lymph nodes • death follows in about 2 years
AIDS: Transmission of HIV • virus is present in bodily fluids: blood, semen, cervical and vaginal secretions • low levels also present in urine, saliva, tears (no evidence that virus can be transmitted by these fluids) • transmitted when contaminated fluid enters another’s body • risk of contraction is greatest in receptive partner during anal or vaginal intercourse • common modes of transmission: use of contaminated needles, sexual contact, during pregnancy
AIDS: Transmission of HIV • virus does not live long outside of the body • cannot be contracted from classroom activities, bathrooms, swimming pools, kissing, sharing food, coughing, sneezing, sweating, sharing utensils, giving blood
Pregnancy and HIV • Use of protease inhibitors during pregnancy can reduce risk of infecting fetus (25% to 8%) • HIV-positive women are advised not to breastfeed